THE STORAGE ENVIRONMENT

The storage environment into which a record is placed can have
a dramatic effect on the long-term usefulness of that record and
the information it contains. Key environmental factors are:

temperature

relative humidity

pollutants

light

Air may contain excessive moisture, pollutants,
microorganisms, and other particulates that accelerate the
deterioration of paper. Dirt and dust particles can scratch film
and tape emulsions and carry pollutants that may promote paper
degradation.

Because records do not possess the human ability to
recuperate, we look for preventive means to minimize damage from
the environment. Controlling temperature, relative humidity, and
light and keeping the environment clean can have a dramatic
effect on the longevity of records.

TEMPERATURE AND RELATIVE HUMIDITY

Records exposed to high levels of heat, humidity, light, and
dirt degrade more quickly than records stored under conditions
that are cool, dry, dark, and clean. Research has shown that
cooler temperatures can dramatically reduce the rate of
degradation of all records.

A target temperature and relative humidity for storing records
composed of a variety of materials is 68º F. +/- 2º F and 40%
+/- 5% relative humidity (RH). The true goal is to provide a
stable environment, keeping as close as possible to the levels
suggested with minimal fluctuations. Some heating and cooling
systems come with programmable thermostats that provide varying
temperature schedules. While these may save fuel by shutting down
the system, they will also increase the period of time that
records are not stored under desired conditions. Keep conditions
as consistent as possible. Maintain the
building housing records at the same temperature and relative
humidity 24 hours a day, seven days a week.

Do not store permanent records in barns, equipment sheds, or
any other building without the capacity for heating and cooling
as needed.

MOLD

Excessive heat, poor air circulation, and relative humidity
above 65% can provide a suitable climate for mold growth. High
humidity is especially problematic in basements, where ground
water and cooler temperatures encourage water vapor to collect.
The appearance of mold indicates a serious condition -- take
immediate action.

When mold occurs, reduce the temperature and relative
humidity. Do not move records or try to remove mold from records
without first consulting with preservation personnel.

Determining the mold species is an important first step in
addressing the mold outbreak. Some molds can present very serious
health concerns. Even dormant (dry or powdery) mold spores can be
readily redistributed within a storage space, becoming active
(velvety) when environmental conditions are favorable for growth.

If you discover records with mold, immediately contact the
Conservator, Reference and Preservation Program, Georgia
Department of Archives and History, at 404-656-3554.

Lowering temperature and relative humidity levels and
increasing air circulation are usually required to discourage
future mold growth.

LIGHT

Light, whether natural or artificial, can weaken some
materials, causing them to fade or darken. Damage from light is
irreversible, and the effects of exposure accumulate over time. A
record exposed to a dim light for a long time will ultimately
show the same effects as a record exposed to a bright light for a
short time. Reduce exposure to the greatest degree possible.

Cover windows with shades or drapes that block light entirely.
Blocking light in this manner will also help keep a more stable
temperature by reducing solar heat gain. Turn off interior lights
when not in use. Storing materials in folders and boxes is an
excellent way to protect records from light.

Photocopiers can be a powerful source of light. Avoid
repeatedly copying the same record. Create "surrogates"
or use copies for heavily requested records. Provide users with
surrogate copies to reduce wear and tear on originals.

DUST AND POLLUTANTS

State-of-the-art repositories use chemical filtration to
remove pollutants from the air. Even without an expensive
filtration system, there are a number of ways to limit the
effects of pollutants.

One important way is to house records within folders and boxes
that meet the American National Standards Institute (ANSI)
standard for permanence, Z39.48-1992. The alkaline reserve in
these materials will serve as a buffer between the contents and a
potentially harsh environment. Boxes and folders meeting the ANSI
standard will create a stable micro-environment for permanent
records.

Maintain an overall environment that is as dust-free as
possible.

Change furnace and air conditioner filters on a regular
schedule, e.g., quarterly.

Use vacuum cleaners equipped with high-efficiency,
particulate air (HEPA) filters if possible, so as not to
redistribute dust.

Do not store records near copying machines, which produce
ozone and dust from toner.

PESTS

A pest infestation not only creates anxiety among staff -- it
can cause significant damage to records. Insects are generally a
barometer of another environmental problem, such as high relative
humidity, gaps in the building envelope, or poor housekeeping.

Remove trash daily from inside the building, and do not allow
collected trash to accumulate in areas directly outside the
building. A clean and environmentally-controlled building will
discourage pests from making their home in storage areas.

Unless there is a specific problem to be addressed, avoid
regularly scheduled chemical treatments. There is no
all-purpose chemical for eliminating every pest problem.
Moreover, chemicals that emit strong odors may create long-term
problems for staff, records, and record users. Glue traps contain
no chemicals and are useful for determining the existence and
type of pest present. Such monitoring devices can be furnished by
your local pest control technician or purchased in hardware
stores.

Limiting food and beverages to designated areas, monitoring
the environment, using identification and least toxic eradication
methods first, and working with your
pest control technician are all part of a preventive approach
known as integrated pest management, or
IPM.